Molecular Phenotyping Core The Molecular Phenotyping Cere will provide analytical tools te the MNORC investigators to permit structural identification and quantification ef metabolites and perform functional metabolic studies. In addition to providing instrumental infrastructure, the Cere staff will provide consultation and collaboration te apply metabolomic platforms in nutrition and obesity research. Where needed, the Cere laboratories will assist in development of new analytical methods te meet the research objectives of the investigators. The Molecular Phenotyping Core will optimize the efficiency and cost-effectiveness by providing these services te MNORC investigators through a central laboratory. This avoids the need for individual investigators te purchase and maintain high price instrumentation in their own laboratories and avoids the high cost of commercial analytical services. In the past three years we have standardized and implemented several analytical techniques for the analysis of small molecule metabolites such as amine acid, lipid and nucleic acid metabolites in samples from murine, rodent and human tissues, plasma, and urine, and cultured cells. Emphasis will also be placed on fulfilling the needs ef Investigators efthe MNORC who will gain maximum benefit from the power of mass spectrometric analysis. We are particularly interested in addressing three areas ef need: first, applying the unique sensitivity and specificity ef mass spectrometry te detect and quantify lew abundance molecules of interest in nutrition research; second, the develepment ef innovative mass spectrometric techniques for the detection and structural elucidation of nutrition-related biomolecules; and three, providing MS training for graduate students and postdoctoral fellows with an interest in nutrition research. By centralizing and standardizing procedures, the Core provides a common set ef analytical tools that will lead to a unified understanding of molecular mechanisms involved in physiologic and pathophysiologic precesses underlying obesity and other nutrition related disorders.